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Each year, fans look forward to the Home Run Derby even if managers of the competing players often cringe. While the derby usually lights up the night, statistics show it is the catalyst for a second-half power outage.
It is easy to say the derby has an adverse effect because players alter their natural swings to hit more home runs. Statistically this is hard to prove, but Bobby Abreu's(notes) second-half collapse in 2005 got us thinking.
Bobby Abreu won in 2005.
Abreu's record of 41 derby home runs should have been a prelude to a huge second half. Instead, it seemed like a curse that plagued him for the rest of the year. He finished with only six homers after the break, highlighting a negative trend that sees derby contestants struggling for the remainder of that season.
In looking at the 40 finalists and semi-finalists over the past 10 years, statistics show 60 percent of players saw a decrease in slugging percentage. Of those 24 players, nine suffered what can be considered a major loss of power (-0.100 in slugging percentage). In comparison only two players gained that much in slugging percentage.
Players chosen for the Home Run Derby are top hitters from the first half of the season (this season captains were named to select the AL and NL sides). Some players have been invited on the strength of a great first half of the season. These are the players who fit the profile for a substantial decline in the second half.
If you are going to take this kind of look at the Home Run Derby participants, it is also necessary to look at the sluggers that did not compete. AccuScore looked at the top five home run hitters who did not participate in the derby for each of the past 10 seasons. A whopping 70 percent of those players actually improved their slugging percentage after the All-Star break.
The Home Run Derby curse is real. Since 2001, derby participants have averaged a .025 decline in slugging percentage. The top home run hitters who did not participate averaged a .036 increase in slugging.